Submission #298023

#	Time	Username	Problem	Language	Result	Execution time	Memory
298023		miss_robot	Strange Device (APIO19_strange_device)	C++14	100 / 100	566 ms	65872 KiB

strange_device

#include <bits/stdc++.h>

#pragma GCC optimize("O3")
#define int long long

using namespace std;

const int N = 1152921504606846976;
int sol, n, a, b, l, r, cycle, last = -1, tl;

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cin >> n >> a >> b;
	vector< pair<int, int> > qry, iv;
	while(n--){
		cin >> l >> r;
		qry.push_back({l, r});
	}
	int temp = __gcd(a, b+1);
	if((a/temp) <= N/b) cycle = (a/temp)*b;
	for(auto &t : qry){
		tie(l, r) = t;
		if(cycle && r-l+1 >= cycle){
			cout << cycle << "\n";
			return 0;
		}
		if(cycle) l %= cycle, r %= cycle;
		if(l <= r) iv.push_back({l, r});
		else iv.push_back({0, r}), iv.push_back({l, cycle-1});
	}
	sort(iv.begin(), iv.end());
	for(auto &t : iv){
		tie(l, r) = t;
		if(last == -1) tl = r, last = l;
		else if(tl < l){
			sol += tl-last+1;
			tl = r, last = l;
		}
		else tl = max(tl, r);
	}
	if(last != -1) sol += tl-last+1;
	cout << sol << "\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20
• Subtask 8: 30 / 30